The first 3:30 in game time is about surviving cheese often by controlling drones well. If you follow a standard build order, at 3:30 you should have three hatches completed and three queens.
This build focuses on surviving from 3:30 to 5:30 growing your drones from 33 to 66. My strategy is to get 66 drones although 40-80 are other good numbers to go for it's up to your preference.
The first key concept is that your primary focus should be making drones as fast as possible. Any delays have a massive impact. Any distractions that lead you to forget to get drones with your bank is a big problem. So focus very much on droning which also means don't get supply blocked.
The second and final concept is to survive. To do this choose how many queens you want per matchup or just make 2 at a time from the natural and third constantly until 5:30. Also you want lings just for spotting move outs and their expansions (overall just map vision from lings 25 minerals each, maybe spotting a proxy base or proxy pylon that they plan to make DT from). Next you want three buildings when you get a chance: Nest, Warren, and Lair. Lastly you want to remember to sac an overlord quickly at this phase. I normally send two in. For ZvZ you don't sac but instead you do want to spot when they don't have a third at 3:30. If they don't you can ensure you have three on gas and get a lair and overseer quickly. This allows you to scout for a spire, if no spire it's likely a nydus Roach or just roach timing, usually 40-50 drones and roaches yourself are good or if spire then two spores per mineral field, hydra defense, into lurker move out is okay. I feel like Muta fake into 0-5 Mutas then mass roach Baneling is dangerous so watch out for that if you begin making hydras (maybe only make many hydra if you see many muta first).
For 5:30+ you have 66 drones so just use overseer to scout and counter the enemy. If not yet sure how to counter them at least start with ling/bane in ZvT, roach/ravager in zvz, and ling/bane roach/ravager in zvp (exception is queen is better than ling/bane roach/ravager if you see void Ray or carrier Opener, just be careful void Ray Opener might overwhelm you with a ground army). The reason is that you need lings/roaches as your mineral sink so they are in every early army. This gives you time to scout more and react. Terran is hard to engage into until hive tech mostly viper or ultra. Broodlord is rare to get only if like 20 tanks.
If you defend an all-in, counter attack with Banelings and lings if 20-39 workers and use a mix of Roach Ravager Queen (OL or nydus to carry queens) if 40-59 workers.
If you fail to counter someone like mass cyclone hellion you can try custom game search "LOTV" > Unit tester LOTV vs AI to practice different ideas to see what is most cost efficient vs what you lost against. Like Infestors are a good unit to add vs cyclone hellion or even vipers (so spellcasters mainly).
Sorry if any information was extra but the main build is short for memory.